title: Time-specific effect of prenatal stressful life events on gestational weight gain.
abstract: OBJECTIVE
  To investigate the time-specific effect of maternal exposure to prenatal stressful life events (SLEs) on gestational weight gain (GWG) and to determine whether pre-pregnancy body mass index (BMI) modifies the effect.
  
  
  METHODS
  Between March and November 2008, data were collected from 1800 pregnant women who received prenatal check-ups in Hefei, China, after 32 completed weeks of gestation. Participants completed a structured interview on demographic characteristics and a checklist of SLEs during different stages of pregnancy. GWG during pregnancy was determined by self-reported pre-pregnancy weight and measured weight at delivery.
  
  
  RESULTS
  There was a significant dose-response relationship between prenatal SLEs in the first, but not the second or third, trimester and GWG. For each 1-unit increase in SLEs during the first trimester, there was a reduction in GWG of approximately 0.497 kg (95% confidence interval, 0.176-0.817 kg). After stratification by pre-pregnancy BMI, a significant negative association between SLEs in the first trimester and GWG was observed among women with pre-pregnancy normal (β=-0.796; 95% CI, -1.291 to -0.301) and low (β=-1.066; 95% CI, -2.180 to -0.048) weight.
  
  
  CONCLUSIONS
  The effect of prenatal SLEs on GWG depends on the timing of maternal exposure to stress and varies according to pre-pregnancy BMI.
authors.affiliation: Department of Maternal and Child Health, School of Public Health, Anhui Medical University, Hefei, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhu
authors.forename: Wen
authors.initials: W
authors.lastname: Huang
authors.forename: Jia-Hu
authors.initials: JH
authors.lastname: Hao
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Jiang
authors.forename: Fang-Biao
authors.initials: FB
authors.lastname: Tao
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002681:China; D005260:Female; D006801:Humans; D008016:Life Change Events; D011247:Pregnancy; D011248:Pregnancy Complications / Q000523:psychology*; D011261:Pregnancy Trimester, First / Q000523:psychology; D011262:Pregnancy Trimester, Second / Q000523:psychology; D011263:Pregnancy Trimester, Third / Q000523:psychology; D013315:Stress, Psychological / Q000523:psychology*; D013997:Time Factors; D015430:Weight Gain; D055815:Young Adult
keywords: Body mass index; Gestational weight gain; Life events; Pregnancy; Psychosocial stress